Preparing your pet for travel: Crate requirements

Importance of travel crate acclimation

It's very important to make sure your pet is accustomed to being in a crate designed for airline travel, which is different from a wire training or sleeping crate. To make sure your pet is ready for their trip, you should get the travel crate as far in advance as possible — at least two or three weeks before your pet's travel, though we recommend earlier than that to properly acclimate your pet to their crate. This process is called "crate acclimation." It's crucial that your pet is comfortable and feels secure in their crate to reduce their stress during their trip. Please watch this video for tips on how to acclimate your pet.

Your pet's safety and welfare are very important to us, so please keep in mind that if your pet shows signs that they're not acclimated to the crate, or appears to be highly stressed during check-in, United may determine that your pet isn't ready to fly and may refuse acceptance for travel.

  • Pets traveling with United PetSafe must use an approved crate that meets United Airlines, USDA and International Air Transport Association (IATA) requirements. United's crate requirements are based on USDA and IATA standards.

    Approved crates are available for purchase at many pet supply retailers, as well as directly through our partner Petmate at (Use promo code UAFREESHIP at checkout for free shipping of some crate sizes. Shipping of crates purchased from Petmate is available within the contiguous U.S. only)

    It's important to note that while retailers may say a crate is "airline approved," the crate must meet all the requirements listed below to be accepted for travel with United's PetSafe program. Compliant crates must be purchased in advance of travel to allow time for proper acclimation.

    You'll need to submit photos of your pet's crate for pre-approval after you book their trip, but we only approve the construction of the crate beforehand. When you drop them off at the airport on travel day, we'll determine if the crate is the right size for your pet. For your pet's safety, acceptance for travel is always subject to final review, inspection and approval by United PetSafe when your pet is checked in for their flight.

    If we see that a crate doesn't meet United's requirements or isn't the appropriate size for your pet at check-in, we won't accept your pet for travel and you'll need to make alternative arrangements for your pet's trip, which might include purchasing a new crate that meets our requirements.

    Please note that crates are no longer available for sale or exchange by customers at United PetSafe acceptance facilities.

  • United no longer accepts crates that exceed 34 inches in height for transport with our PetSafe program.

    Each pet in the crate must have enough space to stand, turn around normally while standing, sit up and lie down in a natural position.

    Please watch this videofor information on how to choose the right crate for your pet.

    *Not all crate sizes will fit on all aircraft. Please see the standard crate types chart for more details.

  • The crate types below are accepted on most United aircraft and are available for purchase through our partner Petmate (except 600/PP90 size) at

    For dogs that are slightly too large to fit in a 40" L x 27" W x 30" H crate (500 size), PetSafe now accepts crates up to 34" in height (which includes 600/PP90 size) or 500-sized crates with a 3-inch extension kit on mainline aircraft. 600/PP90 size crates can be purchased directly through PetExpress.

    Extension kits for standard 500-sized crates can be purchased through KC Pets or from other pet supply retailers.

    Standard crate types table
    Crate type(#) footnote*Crate size (in.)Estimated crate weight (lb.)Aircraft type acceptance
    10021 L x 16 W x 15 H7All United aircraft footnote*
    20028 L x 20.5 W x 21.5 H13All United aircraft footnote*
    30032 L x 22.5 W x 24 H18All United aircraft footnote*
    40036 L x 25 W x 27 H24All United aircraft footnote*
    50040 L x 27 W x 30 H32All United mainline aircraft footnote*
    600/PP90 footnote**52 L x 32 W x 32.5 H47All United mainline aircraft footnote*
    Embargoed – United will not accept the following:   
    70048 L x 32 W x 35 H51No United aircraft

    *Crate acceptance guidelines noted above apply to United aircraft – maximum height cannot exceed 34" for any crate. Limitations apply for travel on United Express® flights. The #400 series is the largest crate size accepted on United Express aircraft, and not all United Express aircraft are able to accommodate pet crates. Please call United PetSafe at 1-800-575-3335 to verify crate accommodation.

    **600/PP90 crates can be purchased through PetExpress. The dimensions included above are for PP90 crates, but the dimensions for 600-sized crates may vary.

  • Crate ventilation

    Each crate must have ventilation on three sides for travel within the U.S. and Puerto Rico, and ventilation on four sides for travel to or from all other locations.

    Crate must:

    • Be made of rigid plastic, wood or metal that’s sturdy enough to resist bending when firm pressure is applied
    • Have a solid roof with no doors or ventilation openings
    • Have only one metal door which must close securely, yet allow pets to be accessible in the event of an emergency
    • Have crate hardware that’s in good working condition
    • Have a nut and bolt firmly tightened in each hole that connects the top and bottom of the crate. The bolt must be made of metal. The nut may be metal, nylon or plastic as long as the nut is unbreakable and securely connects the top and bottom of the crate.

    The crate must not:

    • Have door openings on top, or have more than one door
    • Be made entirely of cardboard, welded or wire mesh, wicker or other collapsible materials
    • Have a plastic or fiberglass door
    • Have side plastic latches, unless additional holes have been drilled and metal bolts have been added to secure the crate
    • Have crate wheels, unless they are removed, locked or firmly taped to keep the crate from rolling while in transit.
    • Be constructed of plastic that will bend when pressure is applied
    Example of an unacceptable crate that bends under pressure
    Examples of acceptable crates
    Examples of unacceptable crates
    • Crates cannot be more than 34 inches (86.4 cm) in height.
    • 700 series (Giant) crates are no longer accepted by United.
    • Only one adult cat or dog can travel in a crate.
      • Two kittens or puppies younger than six months can travel in a crate together as long as they’re similar in size and weigh less than 20 pounds (9 kg.) each. The crate must allow the kittens or puppies to move about freely.
    • Dogs and cats, or kittens and puppies, can’t travel together in a single crate.
  • If your dog displays behaviors such as excessive chewing or clawing, even after they're acclimated to a travel crate, we strongly recommend that you use a reinforced crate that meets specific international requirements (IATA Container Requirement #82) for increased safety. United may also, in its sole discretion, not accept your pet for transport if your pet excessively chews, claws or exhibits any other behavior that shows your pet is not acclimated to the crate during check-in.

    Reinforced crates must:

    • Be constructed of materials that can't be damaged by a pet biting or scratching, including wood, metal, synthetic materials, or welded or wire mesh. Reinforced crates can't contain plastic in any part of their construction.
    • Have only one door made of metal, heavy wire mesh or reinforced wood. The door must have a secure fastening that can't be opened accidentally.
    • Meet our crate ventilation requirements
    • Have a leak-proof floor that keeps urine and excreta from leaking out of the crate
    • Have ventilation openings narrow enough to prevent the pet's nose or paws from protruding outside the crate

    NOTE: Some commercially-made metal crates may be used as reinforced crates; however, custom modifications are often required to make sure a pet's nose or paws don't protrude outside the crate. Not all crate sizes will fit on all aircraft. Please see the standard crate types chart for more details.